The year is 1975: ‘Jaws,’ the greatest shark movie ever made is released, a film with a perfect cast, expertly-crafted scares, an unforgettable soundtrack, and one of the most satisfying villain endings ever filmed. The film ushers in the age of the summer blockbuster, and propels Steven Spielberg into a career as one of the best filmmakers of his day.

Fast-forward to 1987. ‘Jaws the Revenge,’ one of the most reviled shark movies ever made, is released, a film starring Michael Caine as a man named after a sandwich, a shark who’s mechanical innards can frequently be seen as it lurches around the Bahamas seeking revenge on the Brody family, and an ending where a toy shark in a swimming pool explodes after being gently touched by a wooden bowsprit. The film ushers in the end of the Jaws franchise, and becomes a laughingstock among fans of cinema.

What on earth happened?

Lighting, as the old saying goes, never hits the same place twice. Although it only had three sequels, the Jaws series is one of the most infamous examples of a franchise that started out perfectly before ending with a dud. Although there are many lessons to be learned from the series on how not to handle sequels, one lesson stands above the rest:

When a story’s conflict has been resolved, it’s time for the story to end.

Perfect film that it is, ‘Jaws’ is not an epic that can be told as a trilogy in the vein of ‘Star Wars’ or ‘Lord of the Rings.’ It’s a small-scale, self-contained story centered around a single community with a clear beginning, middle, and end. It has a conflict (a shark terrorizing a coastal town) with a definitive ending (said shark is blown to pieces) in which Amity is saved, and the story has come to its logical end with no loose threads or ideas that could be explored in a sequel. ‘Jaws’ does not lend itself to further stories of Martin Brody fighting off shark after shark, year after year, and yet we got three more stories that now serve as poster children for unnecessary sequels.

Now, this is not to say that ‘Jaws 2,’ ‘3,’ and ‘The Revenge’ don’t have their merits. As previous installments in this series have shown, each one has moments, scenes, and ideas that are quite good.

But there’s a theme running through all the Jaws movies that I never noticed until re-watching them: coming to terms with trauma. The first film has Quint’s legendary recollection of surviving the sinking of the USS Indianapolis, ‘2’ has Martin dealing with the PTSD of going face to face with a shark, and ‘Revenge’ has Ellen dealing with losing both a son and her husband to the sharks. Much like Ellen Ripley in ‘Aliens,’ the original film, ‘2,’ and ‘Revenge’ are at their strongest when they focus on Quint, Martin and Ellen dealing with the trauma they’ve endured from the sharks, helping make them so much more memorable than cookie-cutter protagonists who exist to provide cheap thrills via their inevitable, bloody deaths.

But it’s not just trauma that was an unexpected find when re-watching the movies. I was surprised to find that, out of the three sequels, I actually enjoyed ‘Revenge’ the most. Not because it’s a good film (though it is a satisfying guilty pleasure), but because, out of all three sequels, it’s the one that tries the most to do something new while moving the story forward. ‘2’, while the best of the three, is still largely a copy of the first film, and ‘3’ has nothing in common with the rest of the series (aside from Sean, Michael, and a shark), but ‘Revenge’ doesn’t repeat the ‘shark attacks Amity’ plot. Though its new ideas weren’t that great (dooming it before a single shot was filmed), ‘Revenge’ at least tried to do its own thing and escape the shadow of its predecessor, and for that it deserves recognition.

While all four films offer many character moments, story ideas, and themes that are valuable to learn from, I believe that if we were to condense all those lessons down, these are the three most valuable:

1. When a story’s conflict has been resolved, it’s time for the story to end.

2. Having characters struggle to overcome traumatic events makes them more interesting to watch.

3. When writing a sequel to a self-contained story, try to follow the same spirit as the original, but avoid copying the story and conflict.

Valuable lessons, indeed, but ones that came at a high cost: Although it’s been over 30 years since ‘Revenge’ was released, it seems unlikely that we’ll see another Jaws film anytime soon, if ever. And you know what? Maybe that’s for the best (if nothing else, ‘Revenge’s poor showing prevented the series from eventually heading into outer space). If the Jaws series proves only one thing, it’s that if you really want to honor a story you love, leave it be. Let it stand on its own and not taint it with inferior and unnecessary followups. Let other stories in the same genre tell their tale without the burden of having to live up to a masterpiece.

Oh, and avoid having your sharks roar. That’s just silly.